82, 70, 76, 64, 70, 58 ,?

The series alternately subtracts 12 and adds 6: 82 − 12 = 70, 70 + 6 = 76, 76 − 12 = 64, 64 + 6 = 70, 70 − 12 = 58, and next 58 + 6 = 64.